On 04.04.17 12:29, Gene Heskett wrote: > On Tuesday 04 April 2017 06:04:50 Erik Christiansen wrote: > > > On 04.04.17 05:00, Gene Heskett wrote: > Those scraps of that blueish foam have all been binned or used years ago. > And Lowes no longer carries that same board in 2" R22 thickness. The > current product the last time I looked is a white, larger cell product > and only about R20 because of that, but its the same $35 & tax a 4x8 > foot sheet. How it would cut with a hot wire would be TBD.
Should be good. It's when resorting to a cold sharp knife that the "melded bean bag fill" crummy foam crumbles. ... > How hot does the hot wire need to be? Just go by feel. This one suggests 600°F (that's 315°C, which sounds like a good starting point): https://www.youtube.com/watch?v=3GWzHb4Hd8Y but with a 555 & MOSFET, you can PWM your way to happy cutting from 12v with most bits of recycled nichrome wire even a foot long. Some make the frame from wood - that'd be more rigid than his. (I've welded a couple of small bits of RHS together, added a baseplate to screw to an old chipboard kitchen sink cutout (melamine topped), and need to rout a slot from the edge to the base of the wire, for an Al T-slot, so I can slide a vertical pin back & forth for setting radii for cutting disks, rings, and cylinders. > Seeing as how thats best jiggered up as a wire support frame I could > stick in a vise on the g0704's table and rig some sort of a sheet > gripper leaving a cutaway, for the hot wire to move within, attached > to the chip pan, if I get it rigid enough to keep its place as the > wire moves, I could probably just write gcode to drive the cutters > path. Where it needs a lid like the outside face of a belt cover, just > cut the outline out and glue it on. Takes a while to build, though. Sketching the outline on the back of a cornflakes packet, cutting it out with scissors, running around it with a ballpoint pen on the foam, then carefully following it by hand with the hot-wire cutter, is quicker. (I don't know of a good temporary adhesive for sticking the template on the foam without tearout on removal.) > But, I think buying the printer would get me a nicer looking belt cover. The printed product could perhaps be used directly, instead of then making a casting, and machining it where necessary? Erik ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
